Gripper for tuft weaving looms



Patented Aug. 4, 1931 UNITED STATES APafrstrr erica HENRY WILLIAM SHANNON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO WORCESTER LOOM WORKS, OF WORCESTER, MIASSACHUSETTS GRIPPER FOR TUFT WEAVING LOOMS Application filed January 23, 1930. Serial' No. 422,805.

My invention relatesto grippers for tuft weaving looms, in which the tuft yarns are drawn either from'ryarn carriers or from tuft frames by a series of grippers which, after the tuft is cut ofi', carry the severed yarns down to the fell of the fabric. `The patent to Pearsall #853,471 shows somewhat similar grippers drawing the tuft yarns from yarn carriers while the patent to Alvord #1,436,-

,619 shows the tuft frame type of loom.

- The gripper shown in this instance is of a different type from those illustrated in the above mentioned patents the chief difference beingin ythe method of pivoting the jaw on the body. As will be pointed out later I employ a spring steel retaining disk riveted tothe body instead of the usual central pivot rivet, and itis the object of my invention to produce a disk which will lie flat and iiush with the gripper surface. Another object of my invention is an improved method of eliminating loose gripper jaws which tend to produce uneven pile.

With the above and other objects in view my invention kconsists of the construction disclosed in the drawings and specification and then more particularly pointed out in the appended claims.

.In the drawings Fig. 1 shows a full size view of a gripper with my new type of disk riveted thereto; Fig. 2 is an enlarged cross ysection taken on A-A of Fig. l; and Fig. 3

is an enlarged vperspective view of my disk and'F ig. 4 is an enlarged side elevation of my new disk. l

. Referring to Figs. 1 and 2 it willbe seen that the gripper iody 1 is provided with counterbore pilot hole 2, used while machining the part, and concentric therewith is a circular groove 3. The lower surface of jawl 4 is counterbored leaving a circular ring-or shoulder 5 which seats inrgroove 3 with' suffi-y Y cient freedom yto afford an easy working pivoted joint. The upper surfaces of both jaw and body are counterbored at 6 to provide l a recess for the spring steel retaining disk 7 which is riveted to the body 1 by rivets 8, 9

and 10.

In actual practice the diameter of disk 7 is about 11/4 while the rivets are only about l in diameter. It has been found that a slight inaccuracy in drilling the three rivet holes in the gripper body or any irregularity in the concentricity of the rivet holes in the disk may result in buckling the disk when riveted in place so that the edge of the disk may turn upl and project beyond the main surface of the gripper. A gripper in such a condition cannot be used in a loom as the protruding edge of the disk will catch on the reed or on the warp threads, the former causing a smash and the latter a broken warp thread.

To overcome this difficulty I bend the disk as shown in Figs. 3 and 4. Referring to Fig. 3 it will be seen that the triangular area lying within imaginary straight lines drawn tangent to the periphery of the three rivet holes is a plane area with the rivet holes piercing this area. The three segments outside of the plane area are slightly bent backward forming a convex-like and flexible disk. The disk is then attached to the gripper, conveX side up. The rivets are firmly tightened up so the disk flattens out practically to a plane surface but, due to the bend between rivets 8 and 9, there is no chance of the edge of the disk protruding above the surface of the jaw. The pressure of the disk upon the jaw due to this bend causes just the proper amount of friction to keep the jaw from mov-v ing too freely on its pivot as is the case when a fiat disk is used. The bends outside of the imaginary lines tangent to rivets 8 and 10 and 9 and 10 tend to keep the edge of the disk snugly down in its counterbored seat in the gripper body 1. My gripper will thus pass freely between the reeds and the warp threads without catching. Production of the loom is thus increased due to the marked elimination of gripper smashes.

Vhat I claim is:

1. A gripper for tuft weaving looms comprising a body part, a jaw part pivoted thereon, said body and jaw having counterbores to receive a retaining disk and a retaining disk seated in said counterbores and riveted to said body part, said disk normally being of convex configuration before being secured in place.

2. As a neW article of manufacture, sub-` stantially convex retaining disk for a grip# per provided with holes for retaining rivets,

said disk being'a plane surface Within the limits of the area bounded by imaginary lines drawn tangent to the rivet holes.

3'. That-method' of imparting the proper i amount of friction to the jaw of a gripper for tuft Weaving looms which consists in counter- Y boringthe gripper loo'dy andj-avv to receive arretaining disk, ythen applying a "substan tially convexspring steel retaining .disk and riveting the disk securely to theY 'gripper i i body; YHENRY WILLIAM SHANNON. 

